The present invention relates to cut-off machines for material, such as insulation blanket material, supplied in broad rolls; and has particular use in providing adhered insulated linings for sheet metal duct workpieces as they flow along a production line prior to being bent to duct-like shape.
Commercially produced rectangular sheet metal ducts are conventionally made as relatively short standardized duct pieces cut, notched and edged while flowing along a production line. Prior to bending them to rectangular shape, insulation blanket material is adhered to what will become their inner surfaces. The application of the blanket material has not lent itself readily to production line methods.
In somewhat related fields of production, shears have been made to cut lengths of material flowing from rolls while still in motion. Such machine assemblies are commonly referred to as "flying shears". Typically the shear mechanism, or at least its cutting block, starts from rest in an upstream position, and accelerates on downstream until its speed approximates that of the material to be sheared. As its maximum speed is reached, the shear is actuated, but the cutting block mechanism continues its downstream movement as it decelerates. It then reverses its movement to return to upstream position.